Telephone-exchange system



J. A. HALL.

TELEPHONE EXCHANGE SYSTEM APPLICATION FILED NOV. 19, I918.

1,383,804. Patented July 5,1921.

[ L1H C" Mai: Affy.

' /n vemar;

JOHN A. HALL, OF BAYSIDE, NEW" YORK, ASSIGNOR-"TO WESTERN ELECTRIC .GOIVI- PANY, INCORPORATED, OF EW YORK, N. Y., A CO RPOR ATION OF ,YORK

TELEPHONE-EXCHANGE SYSTEM.

Application filed November '19, 1918.

To all whom it may concern V Be it known that I, JOHN A. HALL, a citizen of the United States, residing at Bayside, Lon Island, in the county of Queens, State of lVew York, have invented certain new and useful Improvements in Telephone- Exchange Systems, of which the following is a full, clear, concise, and exact descrlption. H I D This invention relates to improvements-1n automatic telephone exchange systems, and has particular reference to a substation apparatus therefor.

False setting of switches in automatic telephone exchange systemsis often due to ac cidental impulsesproduced in removing a receiver from its switchhook, or in depressing the switchhook inadvertently after the receiver is removed.

An object of this invention is to overcome this difliculty by providing novel means for making the contacts, usually controlled by the switchhook, slow to open after beingclosed by the removalof the receiver, so that should the switchhook be accidentally momentarily depressed, the line circuit will be unaffected thereby. V a

The inventive idea involved is capable of receiving a variety of expressions, some of which, for the purpose of illustrating the invention, are. shown in the accompanying drawing; but it is to be expressly understood that saiddrawing is utilized merely for the purpose of facilitating the description of the invention as a whole and not to definel the limits thereof, reference being had to the appended claims for this purpose.

In the drawing, Figure 1 illustrates diagrammatically a substation apparatus ar-. ranged in accordance with the invention; Fig. .2 is a fragmentary vertical longitudinal section through a desk stand apparatus and showing another form of the invention; Fig.3 is a similar view illustrating still another form of the invention.

Referring to the drawing and more particularly to Fig. 1, the numeral 5 indicates the usual switchhook for supporting the receiver 6. A transmitter 7 is also provided and placed in the circuit of the substation line consisting'of the limbs 8 and 9. Bridging said line is a ringer 10 which is operated Specification ofLetters Patent.

Patented July 5, 1921.

Serial No. 263,138.

of the line circuit directly at theswitchhook upon removal. of the receiver, it is proposed, in the present invention, toprovidean addi-- tlonal contact 12 which is engaged bythe; switchhook to close a circuit fOI'tl18-SlOW-tO-. release relay 13, said circuit bridging thev line. Relay 13 may be made slow to release n any manner well known in the art, and 1n attracting its armature, closes contacts 11 and thus establishes the line circuit which, due to the nature of said relay, will notbe broken by a momentary depression of the switchhook. Transmission of false impulses and consequent incorrect setting of switches will therefore be greatly decreased.

.In practice, when initiating a call, the removal of receiver 6 from the switchhook will initially establish a circuit extending from grounded battery at a primary switch (not shown), limb 8, impulse-sending de vice 14, switchhook 5, contact 12, winding of relay 13 and limb 9 to ground at the above mentioned switch. Relay 13 is energized and, in attracting its, armature, closes the" line circuit at contacts 11, with the result that receiver 6, andtransmit-ter 7 will be lishing a connection, and it will be apparent that if atany'time after the removal of receiver 6 from the switchhook, the latter: should be momentarily depressed or returned, to normal through any cause, the circuit for relay l3 will be broken, but said'r'elay will not release'and its armature Will thereforecontinueto'maintaincontacts 11 closed and no false impulses will be transmitted. Upon restoration of receiver 6, at the termination of the conversation the circuit for relay 13 will be permanently broken at contact 12, and by retracting its-armature will open the line circuit at contacts 11. .1

- Figs. 2 and '3 illustrate other applications of the invention to a desk stand apparatus, but it will be understood, of course, that the constructions shown in said figures may be. applied to wall sets also without departing. from the spirit or scope of the invention. In Fig. 2 standard 15 has mounted therein a supporting element 16 to which is pivoted the. inner end of switchhook "5 for supporting receiver 6, and engaging the downwardly projecting portion of said switchhook is a spring 17 which forces the outer end of switchhook 5 upwardly when the receiver 6 is removed. Also pivoted to supportingit.

element 16 is one end of an angular contactoperating member 18, the other end of which is provided with an insulated abutment 19,

engageable with one of the contacts 20 which.

ber 18, so that upon removal of receiver 6 from said switchhook said pin 21 will swing.

said member about its pivot and cause abutment 19 to exert sufficient pressure upon contact 20, which it engages, to close the several contacts and establish the line circuit.

At the lower end of supporting element 16 the same has preferably pivoted thereto a dash-pot 22 in which a piston 23 is operable. Pivotally connecting said piston with an intermediate point of the contact operating member 18 is a rod 2 1 through the medium of which piston 23 is withdrawn toward the outer end of dash-pot 22, when receiver 6 is removed from switchhook 5. Should said switchhook be depressed, as previously referred to, pin 21 will be momentarily disengaged from the operating member 18, but, due to the cushioning effect of dash-pot 22, piston 23 will not move inwardly sufficiently to permit of contacts 20 disengaging, and the line circuit will therefore be maintained during such a momentary depression. Upon replacing receiver 6 at the termination of the conversation, operating member 18 will be allowed to return toward normal as piston 23 moves inwardly into the dash-pot and pressure of the abutment 19 upon one of the contacts 20 will be relaxed until member 18 has reached its normal position, whereupon said contacts will be opened.

In Fig. 3, a bell crank lever 25 is pivoted at 26 to the supporting element 16. One end of said lever is provided with a cam 27 engaged by pin 28 carried by switchhook 5. Intermediate the pivot point 26 and cam 27 the lever is provided with an insulated abutment 29 engaged by the adjacent one of a plurality of contact spring 30, the tension of which is sufiicient to maintain lever 25 in its normal position against the action of a weight 31 secured to the end of the lever 25 opposite cam 27. Removal of the receiver from the switchhook 5 causes pin 28 to engage cam 27 and rock lever 25 about its pivots in a counter-clockwise direction, and abutment 29 will therefore close contacts 30 and establish the line circuit. Contact 30 engaging abutment 29 is so tensioned as to exert just suflicient pressure upon said abutment to slowly overcome the counter acting eii'ect of weight 31. Therefore should switchhook 5 be momentarily depressed, weight 31 will prevent a quick return of bell crank lever 25 to its normal position under the action of said contact spring, and the line circuit will therefore be maintained unbroken until the receiver has been replaced upon the switchhook, whereupon said contact spring will return lever 25 to normal and the line circuit will be broken.

outgoing line, a substation apparatus con-* nected thereto and including a switchhook and contacts for closing said line, and means at said substation apparatus for preventing the opening of said contacts should the switchhook be momentarily depressed.

3. In a telephone exchange system, an outgoing line, a substation apparatus connected thereto and including a switchhook and contacts controlled thereby for closing said line, and means rendered effective upon removal of the receiver from the switchhook for preventing the opening of said contacts should said switchhook be momentarily depressed.

4:. In a telephone exchange system, an out oing line, a substation apparatus connected thereto and including a switchhook and contacts for closing said line, and electromagnetic means for preventing the open ing of said contacts should the switch hook be momentarily depressed.

5. In a telephone exchange system, an outgoing line, a substation apparatus connected thereto and including a switchhook, and a relay having contacts for closing said line and energized upon the removal of the receiver from said switchhook for preventing the opening of said contacts should the switchhook be momentarily depressed.

6. In a telephone exchange system, an outgoing line, a substation apparatus including a switchhook, a relay having contacts for closing said line, a normally open circuit for said relay bridging said line, and a contact closed upon removal of the receiver from said switchhook for energizing said relay to close the first named contacts and to prevent the opening of said contacts shouldthe circuit for said relay be momentarily broken.

In witness whereof, I hereunto subscribe my name this 14th day of November A. D., 1918.

JOHN A. HALL. 

